Insect control releases thousands of mosquitoes in Florida

40,000 male mosquitoes are being released into the wild every week from now until early July

Insect control releases thousands of mosquitoes in Florida

A female Aedes aegypti mosquito. Image: James Gathany/Cdc/Handout/DPA/PA Images

Authorities in Florida are trialling a novel way to stem the spread of mosquito-borne diseases such as the Zika Virus and Dengue fever.

In what might appear a somewhat counter-productive move - mosquito-control officers are releasing 40,000 male mosquitoes into the wild every week from now until early July.

There is however method to the madness - reported in Science News - as the released insects have been infected with Wolbachia bacteria - that will see their offspring dying before they hatch.

The bacteria render the males biologically incompatible with uninfected females – and authorities hope that over time, the plan will shrink the local population.

Unusual strategy

The strategy runs contrary to other mosquito control efforts – which generally render the insects less susceptible to the disease, while allowing them to carry on as normal.

The first batch of 20,000 insects was released in late-April at 20 pre-determined spots on Stock Island south of Miami.

The Aedes aegypti species of mosquito the control officers are targeting is notoriously difficult to manage and can spread a range of ailments including Yellow Fever and Chikungunya as well as Zika.

Scientists were reportedly able to infect the insects with the bacteria without genetically modifying either species.

Global projects

The Florida project is unique in that only male mosquitoes – which don’t bite – have been released; however there are other projects around the world using a similar technique, but also including females.

Adding females to the mix will allow couples that both carry the bacteria to reproduce – while blocking reproduction with non-bacteria carrying insects.

Eliminate Dengue

Scott O’Neill on Monash University in Melbourne Australia leads the international non-profit, ‘Eliminate Dengue’ which works in developing countries most at risk of disease.

He told Science News the technique can sweep through the mosquito population extremely fast with the mosquitoes themselves doing the leg-work.

He said one of the project’s original release sites in Australia is still humming with Wolbachia-carriers six years on – with no need for additional treatment.

Eliminate Dengue is working in five countries, including in the city of Rio de Janeiro – where the project is treating an area of about 150 square kilometres over the course of two years.